It is known that an analysis of ionizable compounds, such as proteins, can be made by subjecting a sample, of for example blood, to an electrical potential as taught in U.S. Pat. Nos. 3,407,133 (Oliva et al.) and 3,479,265 (Elevitch).
The sample to be analyzed by electrophoresis is placed on a suitable support medium, such as a gel, of the types disclosed in U.S. Pat. No. 3,725,004 (Johnson et al.). Such support medium may include, for example; (1) aqueous solutions of agar or agarose as disclosed in U.S. Pat. Nos. 3,281,409 (Blethen), 3,335,127 (Polson), 3,362,884 (Morse) and 3,766,047 (Elevitch); (2) synthetic polymeric gelling agents as disclosed in U.S. Pat. No. 3,046,201 (White et al.); and (3) cellulose and cellulose acetate as disclosed in U.S. Pat. No. 3,360,440 (Haab et al.). However, such support mediums are prone to dehydration, thus, requiring air tight enclosure by containers to completely prevent evaporation of the water from the support medium as disclosed in U.S. Pat. Nos. 3,875,045 (Bergrahm et al.) and 4,314,897 (Monte et al.). This has been accomplished by providing adhesive sealing strips to the containers, or the use of moistened pads within the containers as disclosed in U.S. Pat. No. 3,856,656 (Brink). Also, such containers have been completely enclosed within air tight bags. Dehydration is undesirable because it affects the shelf life of the support medium and causes variations in the migration of the ionizable compounds during use. In addition to requiring air tight enclosure, such containers have required secure retention of the support medium within the container to prevent the support medium from coming in contact with any part of the container to prevent flaws, such as marks or cracks in the support medium. Such flaws are aggravated by shrinkage of the support medium caused by dehydration as disclosed, for example, in U.S. Pat. No. 4,314,897 (Monte et al.).